Field of the Invention
The present invention relates to a method for scoring a substrate by, for example sandblasting, followed by applying a pigment solution to the substrate surface. More particularly, the invention relates to a method employing an ink-jet printing apparatus to apply substances to the substrate surface.
Description of Related Art
Numerous methods, systems, and devices are known for applying decorative or aesthetically pleasing features to three dimensional, curved surfaces, such an exterior surface of a product, article, or container. Applying a decorative feature such as a design or logo to a manufactured product or article may serve to increase the overall visual appeal of the product, to display information (e.g., slogans, awards and product details), to differentiate a product from competitors, and for branding and advertising purposes.
One simple method for applying a decorative feature to a three-dimensional curved surface is to affix an adhesive label or sticker directly to the surface. The label or sticker can be printed using traditional two-dimensional printing techniques, and then the sticker can be attached to the curved surface. Many disposable products such as cans, bottles, and the like are prepared in this manner. However, stickers or other adhesives are easily removed from the surface. For example, exposure to water, moisture, or heat may weaken the adhesive causing the sticker to fall off the product, article, or container.
Alternatively, decorative features may be printed on a curved surface by a screen printing process. Screen printing is a technique in which a screen is prepared by applying inks or pigment solutions to the screen to form an image. The image contained on the screen is transferred to the substrate by pressing the screen against the substrate. For certain inks or pigment solutions, the screen must be heated or exposed to some other curing agent or condition to cause the ink or pigment solution to affix to the substrate surface. Screen printing is more permanent than affixing a sticker or label to a substrate surface. However, screen printing techniques can be labor intensive and require processing steps including: separation of colors for multi-color designs, preparing the screen, and transferring the screens to the substrate. In addition, the screen may be incorrectly placed on the substrate, meaning that the image will not be aligned or oriented as desired.
Abrasive blasting and acid etching are alternative techniques for providing decorative features to a substrate. These techniques provide a decorative element often referred to as frosted glass. In sandblasting, a mask is placed over a substrate to protect certain portions of the substrate. The substrate is exposed to a stream of a hard particulate media, such as silica, sand, garnet, synthetic particles, or engineered abrasives (i.e., aluminum oxide, silicon carbide, or carborundum). The abrasive stream wears away the portion of the substrate that is not covered by the mask, thereby creating an image or design on the substrate surface. Similarly, in an acid etching process, an acid solution is applied to a substrate surface. The acid solution effectively wears away the portion of the substrate that is not protected by a mask layer.
For some products, the appearance of a sandblasted or acid etched substrate is further enhanced by adding color to the portions of the glass substrate that were worn away by sandblasting or etching. Addition of pigment or paint to the sandblasted or etched portions of the substrate causes the eroded regions to stand out, making these regions easier to view or read. Traditionally, color is added to sandblasted substrates by hand. However, applying pigment by hand to a substrate greatly increases costs of the decorated article. Accordingly, addition of color to a sandblasted article is generally only performed for high cost or custom made pieces. Such design options are not available for low-cost and disposable articles.
Accordingly, there is a need for a method for scoring and then applying pigment to a substrate. The method should permit mass production of articles. Furthermore, the method should apply pigments which are non-toxic, safe for human consumption, and dishwasher safe.